IMPROVEMENT OF THE PHASE-FORMATION AND SUPERCONDUCTIVITY OF THE (BI,PB)(2)SR2CA2CU3OX SILVER-SHEATHED TAPES WITH B2O3 ADDITION

In (Bi,Pb)(2)Sr2Ca2Cu3Ox silver-sheathed (Bi2223/Ag) tapes, melted liq uid phase plays an important role to form the Bi2223 phase. We have ad ded a small amount of B2O3 into Bi2223/Ag tapes to assist in inducing melted phase because B2O3 has a melting point (460 degrees C) much low er than the general sintering temperature of the tapes, and studied th e influence of B2O3 doping on the microstructure and critical current density (J(c)) of Bi2223/Ag tapes. The results show that B2O3 doping i s really effective to result in the faster growth and better alignment of the Bi2223 grains in the superconducting core and improve the magn etic field dependence of the J(c) value. (C) 1998 Elsevier Science B.V .